Blimey, was shocked to see the video myself.
How can a Calculator fail?
If you are a Microsoft fan. Love its Operating systems. Love its applications. Then try this.
Go to Start, All programs and select the Calculator program
Type 4 and click the sqrt button. The answer will be 2. Then subtract the answer with 2.
Shocked with the results? Trust me, even i am!
Heres the video that will explain the process in detail